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Date: Mon, 10 Nov 1997 03:45:09 -0600
To: Mike Smith <mike@smith.net.au>
From: Tony Overfield <tony@dell.com>
Subject: Re: >64MB 
Cc: John-Mark Gurney <gurney_j@resnet.uoregon.edu>,
        Chuck Robey <chuckr@glue.umd.edu>,
        Terry Lambert <tlambert@primenet.com>, jamil@trojanhorse.ml.org,
        hackers@freebsd.org, Jonathan Mini <j_mini@efn.org>
In-Reply-To: <199711070205.MAA00455@word.smith.net.au>
References: <Your message of "Thu, 06 Nov 1997 15:04:48 MDT."             <3.0.3.32.19971106150448.006d5438@bugs.us.dell.com>
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At 12:34 PM 11/7/97 +1030, Mike Smith wrote:
>The kernel is loaded above 1M, so you would have to be careful to make 
>sure that your BIOS calls came out of the lowest 64K.  That could be 
>done with a dispatcher in locore.s though.

I assume you mean the lowest 640K.  But yes, a dispatcher would have 
to exist down there, with a buffer large enough for your INT 13h calls
and etc.

>The other reason is that I don't know how to make the change.  8)  If I 
>did, I'd certainly consider it, although vm86 has a few other uses that 
>argue for using it just out of commonality.

Have you seen this?

/pub/NetBSD-current/src/sys/arch/i386/bioscall/biostramp.S

I don't know if it works, but it looks simple enough.  I do realize it 
offends the sensibilities of some real-mode fearing folks.  

If you can't trust the BIOS after the kernel is in memory, how can you 
trust it to load the kernel into memory?  While the kernel is still 
"booting...", the BIOS should be safe enough to call in real-mode.  

-
Tony